[PATCH] D92154: [AArch64] Add custom lowering for ISD::ABS

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:3981
+                            Op.getOperand(0));
+  // Generate SUBS & CSEL.
+  SDValue Cmp =
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dmgreen wrote:
> Can we just generate a SUBS (which becomes the CMP) and a CSNEG directly? That should avoid needing to create the two sub's I think.
Maybe. I wasn't clear why AArch64 has both AArch64ISD::CSNEG and isel patterns to form CSNEG from CSEL+neg.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D92154/new/

https://reviews.llvm.org/D92154